let Songyu: string | any;
Songyu = 12;
Songyu = "we";
console.log(Songyu);
// 这是没有返回值的
const fn = (arr: number[], arr2: Array<string>): void => {
  console.log(arr);
  console.log(arr2);
};

fn([1, 2, 3], ["a", "b"]);

interface Web {
  name: string;
  age: number;
}

const web: Web = {
  name: "宋宇",
  age: 12,
};

console.log(web);
